raised floor

Raised floors elevate the cleanroom floor to create a plenum space below for utilities, cabling, and air return. **Height**: Typically 12-36 inches (30-90 cm) below floor tiles to structural slab. Varies by utility needs. **Air return**: In many cleanroom designs, air flows down through perforated floor tiles into the sub-floor plenum, then returns to air handlers. **Utilities**: Run power cables, data cables, process piping in the sub-floor space without obstructing cleanroom. **Access**: Floor tiles are removable panels allowing access to utilities below. **Load rating**: Floor tiles rated for weight of equipment, personnel, and vibration requirements. **Dampers**: Adjustable dampers under perforated tiles to balance airflow across cleanroom. **Vibration isolation**: Some tools require vibration-isolated floor sections. Separate pedestals through raised floor to structural slab. **Chemical containment**: Sub-floor may include containment for chemical spills with corrosion-resistant materials. **Comparison**: Alternative is overhead utility distribution with solid floors and air return through walls.